From 9b702505ae13990c2fdad6f544edc7ef62878f55 Mon Sep 17 00:00:00 2001
From: dlg <dlg@openbsd.org>
Date: Tue, 6 Jan 2015 00:38:32 +0000
Subject: [PATCH] implement atomic_swap_{uint,ulong,ptr) and some md variants.
 use these to replace x86_atomic_testset_{u32,u64}.

help from guenther@ kettenis@
ok kettenis@
---
 sys/arch/amd64/amd64/ipi.c      |  4 +--
 sys/arch/amd64/amd64/pmap.c     |  4 +--
 sys/arch/amd64/include/atomic.h | 62 ++++++++++++++++++++++++---------
 3 files changed, 50 insertions(+), 20 deletions(-)

diff --git a/sys/arch/amd64/amd64/ipi.c b/sys/arch/amd64/amd64/ipi.c
index 6f568411e08..48090bb79da 100644
--- a/sys/arch/amd64/amd64/ipi.c
+++ b/sys/arch/amd64/amd64/ipi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ipi.c,v 1.11 2012/12/05 23:20:10 deraadt Exp $	*/
+/*	$OpenBSD: ipi.c,v 1.12 2015/01/06 00:38:32 dlg Exp $	*/
 /*	$NetBSD: ipi.c,v 1.2 2003/03/01 13:05:37 fvdl Exp $	*/
 
 /*-
@@ -103,7 +103,7 @@ x86_ipi_handler(void)
 	u_int32_t pending;
 	int bit;
 
-	pending = x86_atomic_testset_u32(&ci->ci_ipis, 0);
+	pending = atomic_swap_uint(&ci->ci_ipis, 0);
 
 	for (bit = 0; bit < X86_NIPI && pending; bit++) {
 		if (pending & (1<<bit)) {
diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c
index da7b0e8e876..11a69b75e98 100644
--- a/sys/arch/amd64/amd64/pmap.c
+++ b/sys/arch/amd64/amd64/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.83 2014/12/23 07:42:46 tedu Exp $	*/
+/*	$OpenBSD: pmap.c,v 1.84 2015/01/06 00:38:32 dlg Exp $	*/
 /*	$NetBSD: pmap.c,v 1.3 2003/05/08 18:13:13 thorpej Exp $	*/
 
 /*
@@ -216,7 +216,7 @@ pd_entry_t *normal_pdes[] = PDES_INITIALIZER;
 
 #define COUNT(x)	/* nothing */
 
-#define pmap_pte_set(p, n)		x86_atomic_testset_u64(p, n)
+#define pmap_pte_set(p, n)		atomic_swap_64(p, n)
 #define pmap_pte_clearbits(p, b)	x86_atomic_clearbits_u64(p, b)
 #define pmap_pte_setbits(p, b)		x86_atomic_setbits_u64(p, b)
 
diff --git a/sys/arch/amd64/include/atomic.h b/sys/arch/amd64/include/atomic.h
index ae85d5502be..4ec437c2c82 100644
--- a/sys/arch/amd64/include/atomic.h
+++ b/sys/arch/amd64/include/atomic.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atomic.h,v 1.16 2014/10/08 19:40:28 sf Exp $	*/
+/*	$OpenBSD: atomic.h,v 1.17 2015/01/06 00:38:32 dlg Exp $	*/
 /*	$NetBSD: atomic.h,v 1.1 2003/04/26 18:39:37 fvdl Exp $	*/
 
 /*
@@ -88,6 +88,51 @@ _atomic_cas_ptr(volatile void *p, void *e, void *n)
 }
 #define atomic_cas_ptr(_p, _e, _n) _atomic_cas_ptr((_p), (_e), (_n))
 
+static inline unsigned int
+_atomic_swap_uint(volatile unsigned int *p, unsigned int n)
+{
+	__asm volatile("xchgl %0, %1"
+	    : "=a" (n), "=m" (*p)
+	    : "0" (n), "m" (*p));
+
+	return (n);
+}
+#define atomic_swap_uint(_p, _n) _atomic_swap_uint((_p), (_n))
+#define atomic_swap_32(_p, _n) _atomic_swap_uint((_p), (_n))
+
+static inline unsigned long
+_atomic_swap_ulong(volatile unsigned long *p, unsigned long n)
+{
+	__asm volatile("xchgq %0, %1"
+	    : "=a" (n), "=m" (*p)
+	    : "0" (n), "m" (*p));
+
+	return (n);
+}
+#define atomic_swap_ulong(_p, _n) _atomic_swap_ulong((_p), (_n))
+
+static inline uint64_t
+_atomic_swap_64(volatile uint64_t *p, uint64_t n)
+{
+	__asm volatile("xchgq %0, %1"
+	    : "=a" (n), "=m" (*p)
+	    : "0" (n), "m" (*p));
+
+	return (n);
+}
+#define atomic_swap_64(_p, _n) _atomic_swap_64((_p), (_n))
+
+static inline void *
+_atomic_swap_ptr(volatile void *p, void *n)
+{
+	__asm volatile("xchgq %0, %1"
+	    : "=a" (n), "=m" (*(unsigned long *)p)
+	    : "0" (n), "m" (*(unsigned long *)p));
+
+	return (n);
+}
+#define atomic_swap_ptr(_p, _n) _atomic_swap_ptr((_p), (_n))
+
 static inline void
 _atomic_inc_int(volatile unsigned int *p)
 {
@@ -236,21 +281,6 @@ _atomic_sub_long_nv(volatile unsigned long *p, unsigned long v)
 #define virtio_membar_consumer()	__membar("")
 #define virtio_membar_sync()		__membar("mfence")
 
-static __inline u_int64_t
-x86_atomic_testset_u64(volatile u_int64_t *ptr, u_int64_t val)
-{
-	__asm__ volatile ("xchgq %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
-	return val;
-}
-
-static __inline u_int32_t
-x86_atomic_testset_u32(volatile u_int32_t *ptr, u_int32_t val)
-{
-	__asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
-	return val;
-}
-
-
 static __inline void
 x86_atomic_setbits_u32(volatile u_int32_t *ptr, u_int32_t bits)
 {
-- 
2.20.1